WO2014012351A1

WO2014012351A1 - Positioning system of mobile robot and positioning method thereof

Info

Publication number: WO2014012351A1
Application number: PCT/CN2013/000822
Authority: WO
Inventors: 孔钊; 宋强; 姜飞
Original assignee: 苏州科瓴精密机械科技有限公司
Priority date: 2012-07-16
Filing date: 2013-07-05
Publication date: 2014-01-23
Also published as: CN103542846B; CN103542846A

Abstract

A positioning system of a mobile robot (R) comprises some known reflection members, a turntable (T), a laser (J), an angle coder (B), and a central processing unit. A connecting line between adjacent reflection members is enclosed to form a working region of the robot (R). The laser (J) has an emitting portion (J1) and a receiving portion (J2). The central processing unit comprises a graphic processing program for rasterizing the working region, and calculates multiple second angles between connecting lines (L3) formed by connecting each intersection point to each reflection member, and the multiple second angles form a second angle group corresponding to each intersection point. The receiving portion (J2) can simultaneously receive laser rays (L1) reflected by the multiple reflection members, the central processing unit obtains, through computation processing, a third angle group between the laser rays (L1), and the third angle group is compared with the second angle group to obtain the position of the robot (R) in a coordinate system.

Description

Positioning system of mobile robot and positioning method thereof

The invention belongs to the field of positioning technology of a robot, and in particular relates to a positioning system and a positioning method of a mobile robot.

Background technique

In the application of mobile robots, navigation means that the mobile robot senses the environment and its own state through the sensor, and realizes the target-oriented autonomous movement in an environment with obstacles. The success of navigation requires four modules: perception, positioning, cognition, motion control. Among them, positioning is the most basic part of mobile robot navigation. The so-called positioning is to determine the real-time posture of the robot in the environment. The currently used positioning technologies include: visual navigation positioning, global positioning system (GPS), differential GPS positioning, ultrasonic positioning, and so on. Among them, the image processing method of the visual navigation positioning method has a large amount of calculation, and the calculation speed is high, so the real-time performance is poor. In addition, the positioning method is greatly affected by the external environment, and thus is not suitable for the positioning system of the outdoor mobile robot. The Global Positioning System is controlled by the US Department of Defense. For users who are not authorized by the US Department of Defense, the positioning and navigation accuracy that can be obtained is low, so it is not suitable for occasions with high positioning accuracy. Differential GPS positioning refers to a differential reference station with a known accuracy coordinate set near the user's GPS receiver. The receiver of the base station continuously receives GPS navigation signals, and performs measured position or distance data with known position and distance data. Comparing, determining the error, and obtaining accurate correction values, and then transmitting the correction data to the users in the coverage area through the data link to correct the positioning result of the user. Although the positioning method has high positioning accuracy, the cost is high. . For the ultrasonic positioning method, since the ultrasonic wave is greatly attenuated in the air, it is only applicable to a case where the space is small. In view of the shortcomings of the above various positioning technologies, it is necessary to propose an improved mobile robot positioning system to solve the above problems.

Summary of the invention

It is an object of the present invention to provide a positioning system and positioning method for a mobile robot to achieve positioning by angle comparison.

In order to achieve the above object, the present invention adopts the following technical solutions: A positioning system for a mobile robot, the positioning system is disposed in a coordinate system, and the positioning system includes a plurality of reflectors of known coordinate values, and is mounted on the robot 360. . Rotating turntable, laser, angle encoder and central processing unit The laser and the angle encoder are mounted on the turntable; the connection between the adjacent reflective ridges surrounds a working area of the robot; the laser has a transmitting portion and a receiving portion, and the transmitting portion emits a laser emitting line to the The laser reflection line formed by the reflection after the reflector is received by the receiving portion, and the reflector has a function of directing the light of the laser reflection line parallel to the laser emission line; the angle encoder is used for measuring the robot a first angle between the head facing the line and the laser reflected line; the central processing unit includes a graphics processing program, the graphics processing program rasterizes the working area and obtains coordinate values of each intersection The central processing unit calculates a plurality of second angles between the connecting lines formed by connecting the respective reflectors at each intersection, the plurality of second angles forming a second angle group corresponding to each intersection, and then Each second angle group is stored; when the robot moves within the working area, the receiving portion can simultaneously receive the reflection from the plurality of reflectors a light reflection line, the angle encoder may correspondingly measure a plurality of the first angles, and the central processing unit performs an operation process on the first angles to obtain a third angle group between the laser reflection lines, and then The third angle is compared to the second angle to obtain a position of the robot within the coordinate system. .

Preferably, when there is at least two consecutive equal angular values in the stored third angle group, the coordinate value of the robot is the coordinate value of the intersection corresponding to the second angle group. .

Preferably, when the third angle group has only one equal angle value or no equal angle value in any one of the stored second angle groups, the central processing unit will find the angles with the third angle group. Another second set of angles closest to the value, the position of the robot within the coordinate system is closest to the intersection of the other second set of angles.

Preferably, the second angle is an angle between two adjacent connecting lines of the respective connecting lines, and the third angle is between two adjacent laser reflecting lines of the laser reflection lines. angle.

Preferably, the second angle is an angle between one of the connecting lines and the other connecting lines, and the third angle is an angle between one of the laser reflecting lines and the other laser reflecting lines.

Preferably, the mobile robot is a mowing robot.

Preferably, the positioning system further comprises an electronic compass disposed on the robot.

In order to achieve the above object, the present invention can also adopt the following technical solution: A positioning method of a mobile robot on which a 360 can be mounted. a rotating turret, a laser having a transmitting portion and a receiving portion, an angle encoder, and a central processing unit, wherein the laser and the angle encoder are disposed on the turntable, and the positioning method comprises the following steps: 1) setting a plurality of reflectors of known coordinate values in the coordinate system of the robot;

2) the graphics processing program of the central processing unit rasterizes the working area formed by the line enclosing of the reflectors and obtains the coordinate values of the intersections;

3) The central processing unit calculates a plurality of second angles between the connecting lines formed by connecting the respective reflectors at each intersection, and the plurality of second angles constitute a second angle group corresponding to each intersection And then storing each second angle group;

4) when the robot moves in the working area, the laser reflecting line formed by the transmitting portion emitting the laser emitting line to the reflecting member and being reflected by the reflecting portion is received by the receiving portion, and the reflecting member is provided with the laser reflecting line Parallel to the light-emitting function of the laser emission line, and the receiving portion can simultaneously receive a plurality of laser reflection lines reflected from the plurality of reflectors, wherein the angle encoder corresponds to the measured head-to-line of the robot Describe a plurality of first angles between the plurality of laser reflection lines;

5) the central processing unit performs arithmetic processing on the first angles to obtain a third angle group between the respective laser reflection lines;

6) The central processing unit compares the third angle group with the second angle group to obtain a position of the robot within the coordinate system.

Preferably, when the central processing unit finds a second angle group in each stored second angle group, and the second angle group and the third angle group have at least two consecutive equal angle values, the central processing The unit determines that the position of the robot is the position of the intersection corresponding to the second angle group.

Preferably, when the central processing unit does not find the second angle group having the same angle value as the third angle, the central processing unit determines the location of the robot as follows:

1) subtracting the third angle group from each stored angle value in each second angle group, and obtaining a series of fourth angle groups having the same number as the second angle group;

2) comparing the respective angle values in the series of fourth angle groups and selecting the fourth angle group having the smallest absolute value;

3) selecting, from the selected fourth angle group, a fourth angle group having the largest absolute absolute value, thereby obtaining a second angle group corresponding to the fourth angle group;

4) The central processing unit determines that the position of the robot is closest to the position of the intersection corresponding to the second angle group in step 3.

Preferably, when the central processing unit finds a plurality of second angles from each of the stored second angle groups When the plurality of second angle groups and the third angle group are only equal to one circumferential value, the step of the middle processing unit determining the position of the robot is as follows:

1) selecting the plurality of second angle groups from the stored second angle groups;

2) subtracting the third angle group from each angle value in the plurality of second angle groups, and obtaining a plurality of fifth angle groups;

3) comparing the respective angle values in the plurality of fifth angle groups and selecting the fifth angle group having the smallest absolute value;

4) selecting, from the selected fifth angle group, a fifth angle group having the largest absolute absolute value, thereby obtaining a second angle group corresponding to the fifth angle group;

5) The central processing unit determines that the position of the robot is closest to the position of the intersection corresponding to the second angle group in step 4.

Preferably, when the robot moves according to the designated line set by the central processing unit, the central processing unit compares the second and third angle groups at a certain frequency, and the robot moves along the designated line at a certain speed. The steps of the central processing unit to determine the location of the robot are as follows:

1) storing a previous moment position of the robot in the coordinate system when the central processing unit performs the angle comparison in the previous time;

2) The position of the previous moment is the center of the circle, and the circle formed by the product of the frequency and the velocity as the radius is determined as the range of the angle comparison;

3) selecting a plurality of intersections located within the circle or on the circle;

4) comparing the third angle group with a plurality of second angle groups corresponding to the plurality of intersections to obtain a position of the robot within the coordinate system.

Preferably, the robot is mounted with an electronic compass that can measure its navigation direction, and the central processor selects a part of the intersections in the navigation direction of the robot among the plurality of intersections, and then the third angle group and the A portion of the second angle group corresponding to a portion of the intersection is compared to obtain a position within the display system of the robot.

Compared with the prior art, the positioning method of the invention realizes robot positioning by angle comparison, and does not need an overly complicated calculation program, so that not only rapid positioning but also low cost can be realized.

DRAWINGS

1 is a partial structural view of a mobile robot in a positioning system of the present invention. 2 is a schematic view of a head-facing line and a laser reflection line of a mobile robot in a positioning system of the present invention, in which a first angle and a second angle are shown.

Figure 3 is a schematic illustration of the working area of the positioning system of the present invention being rasterized, showing all third angles corresponding to an intersection.

Fig. 4 is a schematic view showing a plurality of laser reflection lines received by a receiving portion in the positioning system of the present invention, wherein a plurality of first angles are displayed.

5 is a schematic diagram of a receiving portion receiving a plurality of laser reflection lines in the positioning system of the present invention, wherein a plurality of first angles in FIG. 4 are calculated to obtain a plurality of second angles between adjacent two laser reflection lines. .

Figure 6 is a schematic illustration of the work area of the positioning system of the present invention being rasterized, showing all of the second angles measured when the mobile robot is in any position.

Figure 7 is a schematic illustration of the third angle of the two connecting edges measured when the mobile robot is in either position in the positioning system of the present invention.

Figure 8 is a schematic illustration of the working area of the positioning system of the present invention being rasterized, wherein the mobile robot moves along a specified straight line.

detailed description

As shown in FIG. 1 and FIG. 2, the present invention provides a mobile robot positioning system, which is located in a plane coordinate system and includes a plurality of reflectors M of known coordinate values and a laser mounted on the turntable T. J and angle encoder B and central processing unit (not shown). In the present embodiment, the mobile robot R is a mowing robot that works on the lawn, so that the entire lawn is the plane in which the coordinate system is located. In addition, in the embodiment, a total of 10 reflectors, M1, M2, ..., M10, are provided, and these reflectors are rod-shaped road signs with a light direct reverse function inserted on the lawn.

Referring to Figures 1 and 2, the turntable T can be 360 with respect to the body of the robot R. In the rotational motion, a laser J is mounted on the turntable T, and the laser J has a transmitting portion J1 and a receiving portion J2. The emitting portion J1 emits a laser emitting line outward. Since the turntable T performs a rotary motion, the laser J also rotates 360° with the turntable T. When the laser emitting line is irradiated onto the reflective member M, it is The reflector is reflected to form a laser reflection line L1. Since the reflector M has a direct light reverse function, the so-called direct light reverse means that the reflected light is parallel to the incident light and the interval between the two is small and can be ignored, so the laser reflection line L1 will Returning to the robot R along the original path of the laser emission line, the returning The flawless ray L1 will receive the Shao J2 reception.

As shown in FIG. 1 and FIG. 2, the turntable T is further provided with an angle encoder B for measuring the head between the head L2 and the laser reflection line L1 of the robot R. a first angle α, the magnitude of the first angle α is that the head of the robot R rotates in a specified direction toward the line L2 to an angle at which the receiving portion J2 receives the laser reflected line L1, in the embodiment. It is specified that the specified direction is clockwise. In addition, since the rotating speed of the turntable is fast, at the same time, the transmitting portion J 1 can simultaneously irradiate a plurality of continuous reflecting members, and the receiving portion J2 can receive a plurality of laser reflecting lines L1, so that the angle encoder can be used. At the same time, a plurality of first angles α are measured, and the central processing unit can perform arithmetic processing on the plurality of first angles α and obtain a third angle β between the adjacent two laser radiation lines L1.

As shown in FIG. 1 to FIG. 3, the present invention also provides a positioning method of the mobile robot R, which includes the following steps:

1) setting a plurality of reflectors of known coordinate values in the coordinate system of the robot R;

2) the graphics processing program of the central processing unit rasterizes the working area formed by the line enclosing of the reflectors 并 and obtains the coordinate values of the intersections;

3) The central processing unit calculates a plurality of second angles 之间 between each of the connecting lines L3 formed by connecting the respective reflectors at each intersection, and the plurality of second angles Θ are corresponding to each intersection a second angle group, and then storing each second angle group;

4) When the robot R moves in the working area, the receiving portion J2 can simultaneously receive a plurality of laser reflection lines L1 reflected from the plurality of reflectors, and the angle encoder Β corresponds to the plurality of measurements Said first angle α;

5) the central processing unit performs arithmetic processing on the first angles α to obtain a third angle group between the respective laser reflection lines L 1 ;

The following will mainly describe how to obtain the position of the robot R within the coordinate system. The working area on the lawn in Figure 3 has been rasterized. The smaller the side length of the grid, the higher the accuracy, so you can set the appropriate accuracy as needed. The working area is rasterized and the coordinates of each intersection can be obtained. One of the intersections is now an example. Since the coordinate values of the reflectors are known, the two adjacent reflectors and the intersection A The second angle 之间 between the two connecting lines L3 can be calculated, which is common in this embodiment. There are 10 inverse angles θ, M2 M10, so there are 10 second angles θ, θ ₂ θ ₁₀ , which form a second angle group corresponding to the intersection point ,, so that the intersection point A can It is represented by this second angle group as Α ( θ, θ ₂ ... θ. In the same way, each second angle group corresponding to other intersections can be obtained. After the program is calculated, the central processing unit Each second angle group corresponding to each intersection is placed in the storage unit. After the above steps are completed, the robot R starts to work, and as shown in FIG. 4 and FIG. 5, when the robot R moves in the work area, The emitting portion J1 of the laser J emits a laser emitting line at a time. Since the receiving portion J2 can receive a plurality of laser reflecting lines L1 at the same time, the receiving portion J2 can receive the reflecting members M1 to M5. The five laser radiation lines L1 are taken as an example. At this time, the angle encoder B can simultaneously obtain five first angles 01, α ₂ , α ₃ , α ₄ α ₅ corresponding thereto. The central processing unit pairs these first angles Perform arithmetic processing to calculate the adjacent two lasers The four third angles between the rays L1 are ο^-α a _r a ₂ , α ₄ -α ₃ , α ₅ -α _{4 , respectively} .

Referring to FIG. 3 and FIG. 6, it can be seen from the above analysis that when the receiving portion J2 can simultaneously receive the laser reflection line L1 reflected from all the reflectors M1, M2 ··..·M10, the central processing unit Simultaneously computing to obtain 10 third angles β corresponding to a set of second angles of the intersection, β ₂ β β, ο, the 10 third angles and the real-time position of the robot R Corresponding to a third angle group, so that the real-time position of the robot R can be represented by the measured third angle group as R (β, β ₂ ... β ₁₀ ). The central processing unit obtains the position of the robot R currently within the coordinate system by comparing a third angle group measured in real time with a second angle group in the storage unit.

The following describes in detail how the central processing unit compares the third angle β with the second angle 而 to obtain the current position of the robot R. When the central processing unit calculates a third angle group β, β ₂ ... β _κι , the third angle group has the following several cases compared with each stored second angle group: 1 The third angle group has at least two consecutive equal angle values with a second angle group in the storage unit; 2) the third angle group has no equal angle value with any one of the second angle groups in the storage unit 3) The third angle group has only one equal angle value with the plurality of second angle groups in the storage unit.

For case 1, as shown in Fig. 7, the measured third angle group β, β _{2 is} assumed. Two consecutive third angles β, β ₂ and two consecutive second angles θ corresponding to a second angle group θ, θ ₂ ... θ _κ in the storage unit, θ _{2 is} equal, for the coordinate values of the known reflectors M1, Μ2, Μ3 and the two triangles ΔΜ1Μ2Ι and A M2M3R of the angle β, β ₂ , the coordinates of the point R of the unique robot can be calculated, so In this case, the current position of the robot R is the second angle group θ, ϋ ₂ Η, ο ^ί^Γ ^ The position of the fork and the point, the coordinate value of the machine R is the coordinate value of the intersection, and the other angle values are not equal to each other mainly due to the error.

For case 2, as shown in FIG. 3 and FIG. 6, the central processor will store the angle value in each second angle group in the storage unit with the measured third angle group β, β ₂ ... The angle value in ₁₍₎ corresponds to the subtraction. Taking the intersection point Α as an example, after subtraction, a fourth angle group θ, -β, θ ₂ -β ₂ ...... θκ, -β, ο, assuming a total of n intersections, there are n fourth angle groups, and the central processing unit compares each angle value in the n fourth angle groups and selects a fourth angle group having a minimum absolute value. Selecting a fourth angle group having the largest absolute absolute value from the selected fourth angle group, thereby obtaining a second angle group corresponding to the fourth angle group ', the second angle group corresponding to The position of the intersection is the closest position of the robot R within the coordinate system.

For case 3, it is assumed that there are a total of m second angle groups in the storage unit having only one angle value identical to the measured third angle group, and the central processing unit first filters the m second angle groups and then applies The same judgment method in Case 2 determines the current position of the robot, that is, the angle subtraction will result in m fifth angle groups, and the central processing unit compares and selects each angle value in the m fifth angle groups. And a fifth angle group having a minimum absolute value, and selecting a fifth angle group having the largest absolute absolute value from the selected fifth angle group, thereby obtaining a second angle corresponding to the fifth angle group The position of the intersection corresponding to the second angle group is the closest position of the robot R in the coordinate system. '' By the description of the situation in the above 3, it can be seen that when the situation 1 occurs, the central processing unit judges and draws the robot position for the shortest time; when the situation 2 occurs, the comparison time is the longest because each intersection is required to be compared. Case 3 does not need to compare all intersections, so the judgment time is less than Case 2. In the actual measurement process, especially when the grid precision is smaller, that is, the longer the grid side length, the probability of occurrence of situation 1 is smaller, and the possibility of occurrence of case 2 and case 3 is the greatest. Although the possibility of occurrence of Case 2 and Case 3 is large, the central processing unit does not need to compare the measured third angle group with the n or m second angle groups each time, because under normal circumstances, the robot R is moved according to the specified line. As shown in Fig. 8, the robot moves along the straight line L4. Assume that the robot moves at a speed of 0.3 m/s, the CPU compares the angle of the angle to 1 time/second, the grid side length is 0.1 m, and the position of the robot R one second is the C point on the line, according to the robot R The moving speed can be considered that the current position of the robot R must be in the circle or circle with the point C as the center and 0.3 meters as the radius. At this time, the central processing unit only needs to be located in the circle. The second angle groups corresponding to the intersections in the circle and on the circle are compared with the measured third angle group, and the comparison method is the same as the three cases described above. In this way, the central processing unit only needs to compare several intersections, so that fast positioning can be achieved. The intersection of the central processing unit to be compared can be further reduced, such as adding an electronic compass. When measuring the direction of the robot, it is only necessary to compare the intersections in the navigation direction, and there is no need to compare them in the navigation direction. . It is really necessary to compare the measured third angle group with the n or m second angle groups only when the position of the previous second of the robot R is unknown, such as the operator moving the robot R to another Position, make it start working again.

The positioning system and the positioning method of the invention realize the positioning of the robot through angle comparison, thereby eliminating the need to write an overly complicated calculation processing program, thereby simplifying the program and reducing the cost; in addition, since the actual processing process, the central processing unit only needs to compare The intersections in a small range, thus enabling rapid positioning of the robot. Description, the positioning system and the positioning method of the present invention have other embodiments, such as the second angle 所述 described in the above embodiment is an angle between two adjacent connecting lines of the respective connecting lines L3, The third angle β is an angle between adjacent laser reflection lines in the respective laser reflection lines L1. The second angle may also be an angle between one of the connecting lines and the other connecting lines, and the third angle may also be an angle between one of the laser reflecting lines and the other laser reflecting lines, and the angle comparison method is the same, the same Robot positioning is possible. Therefore, any technical solution obtained by using equivalent or equivalent conversion means under the guidance of the design concept of the present invention should be within the scope of the present invention.

Claims

Claim

What is claimed is: 1. A positioning system for a mobile robot, the positioning system being disposed in a coordinate system, and the positioning system comprising a plurality of reflectors of known coordinate values, mounted on the robot 360. a rotating turntable, a laser, an angle encoder and a central processing unit, wherein the laser and the angle encoder are mounted on the turntable; the connection between the adjacent reflectors surrounds a working area of the robot; the laser has a transmitting portion and a receiving portion, the laser reflecting line formed by the reflecting portion emitting the laser emitting line to the reflecting member and being reflected by the receiving portion, wherein the reflecting member is provided with the laser reflecting line parallel to the laser emitting line a light direct-reverse function; the angle encoder is configured to measure a first angle between a head orientation line of the robot and the laser reflection line; wherein: the central processing unit includes a graphics processing program, the 'graphic processing The program rasterizes the working area and obtains coordinate values of the intersections, and the central processing unit calculates a plurality of second angles between the connecting lines formed by connecting the respective reflectors at each intersection, a plurality of second angles constituting a second angle group corresponding to each intersection point, and then storing each second angle group; When the working area moves, the receiving part can simultaneously receive the laser reflection lines reflected from the plurality of reflectors, and the angle encoder can correspondingly measure the plurality of the first angles, and the central processing unit Calculating a plurality of first angles to obtain a third angle group between the respective laser reflection lines, and then comparing the third angle group with the second angle group to obtain a robot in the coordinate system The location inside.

The positioning system according to claim 1, wherein: when the third angle group and the stored second angle group have at least two consecutive equal angle values, the coordinate value of the robot is The coordinate value of the intersection corresponding to the second angle group.

The positioning system according to claim 2, wherein: when the third angle group has only one equal angle value or no equal angle value in any one of the stored second angle groups, the central processing The unit will find another second set of angles that are closest to the respective angular values of the third set of angles, the position of the robot within the coordinate system being closest to the intersection corresponding to the other second set of angles.

The positioning system according to claim 3, wherein: the second angle is an angle between two adjacent connecting lines of the respective connecting lines, and the third angle is the lasers The angle between two adjacent laser reflection lines in the reflection line.

The positioning system according to claim 3, wherein: the second angle is an angle between one of the connecting lines and the other connecting lines, and the third angle is one of the laser reflected lines He is eager to stimulate the use of laj without reflection.

The positioning system according to any one of claims 1 to 5, wherein the moving robot is a mowing robot.

7. The positioning system of claim 6 wherein: said positioning system further comprises an electronic compass disposed on the robot.

8. A method of positioning a mobile robot on which a 360 can be mounted. a rotary turret, a laser having a transmitting portion and a receiving portion, an angle encoder, and a central processing unit, wherein the laser and the angle encoder are disposed on the turntable, wherein: the positioning method comprises the following steps:

1) setting a plurality of reflectors of known coordinate values in the coordinate system of the robot;

3) The central processing unit calculates a plurality of second angles between the connecting lines formed by connecting the respective reflectors at each intersection, the plurality of second angles forming a second angle corresponding to each intersection Group, then store each second angle group;

5) the central processing unit performs arithmetic processing on the plurality of first angles to obtain a third angle group between the respective laser reflection lines;

The positioning method according to claim 8, wherein: when the central processing unit finds a second angle group in each of the stored second angle groups, and the second angle group and the third angle group When there are at least two consecutive equal angle values, the central processing unit determines that the position of the robot is the position of the intersection corresponding to the second angle group.

The positioning method according to claim 8, wherein: when the central processing unit does not find a second angle group having an angle value equal to the third angle, the central processing unit determines the robot station ^: Straight under the mouth:

The positioning method according to claim 8, wherein: the central processing unit searches for a plurality of second angle groups from the stored second angle groups, and the plurality of second angle groups and the When the third angle group has only one equal angle value, the central processing unit determines the position of the robot as follows: 1) screening the plurality of second angle groups from the stored second angle groups;

The positioning method according to claim 8, wherein: when the robot moves according to a specified line set by the central processing unit, the central processing unit compares the second and third angle groups at a certain frequency, The robot moves along the designated line at a certain speed, and the central processing unit determines the location of the robot as follows:

2) The position of the previous moment is the center of the circle, and the circle formed by the product of the frequency and the velocity is determined as the range of the angle contrast; 3) selecting a plurality of intersections located within the circle or on the circle;

The positioning method according to claim 12, wherein: the robot is mounted with an electronic compass that can measure its navigation direction, and the central processor selects a part of the plurality of intersections located in the navigation direction of the robot. And intersecting the third angle group with a portion of the second angle group corresponding to the part of the intersection to obtain a position within the coordinate system of the robot.